Tata Steel is facing a criminal investigation into the UK business it is trying to sell, according to the Telegraph.
The report claims Tata referred itself to the Serious Fraud Office (SFO) following an internal audit. "Well-placed sources" say certain certificates which outline the composition of products may have been falsified.
The SFO does not comment on individual cases, but the Telegraph claims the investigation is focusing on documents affecting around 500 customers from one of its site in Yorkshire.
The news of a criminal investigation comes as the company nears an agreement over the sale of its Scunthorpe plant, which could be agreed by as soon as Monday, saving nearly 5,000 jobs.
According to the BBC, Greybull Capital will buy the plant, which has been up-for-sale since 2014, with a £400 million investment package.
Greybull has been in talks to buy the Scunthorpe plant for around nine months, long before Tata announced its decision to sell its entire UK business. The company believes the plant can return to profit within a maximum of two years.
It has been in negotiations with the government over a £70-100m loan to fund part of its investment. As part of the deal, staff are responding to a request to accept a 3% pay cut for one year. Greybull Capital doesn't expect to make more job cuts that the 1,200 already announced in October.
Greybull Capital specialises in company turnarounds. It bought a 90% stake in troubled airline, Monarch, and returned it to profit a year later. And last year, it bought 140 of Morrisons' convenience stores.
It comes as unions, politicians and Tata continue to try to find a buyer for the rest of its UK business. Business secretary Sajid Javid also expects Tata to start the formal process of selling its plants on Monday. Upon returning from talks in India, Mr Javid said Tata would be a "responsible seller".